How do you guys find profitable Products or Niches?

A New Amazon Seller here.

I am having quite a hard time finding products to sell. I am looking for products that have low competition but can provide a sustainable income.

Only type of products I am finding are either very High comp. (big brands already own that market), or the products that have such low competition & income that they aren’t worth leaving my 9-5 job over.

How do you guys find products to sell?

And, do you guys stick to the same niche or change according to trend & market demand?